The Prophet of Yonwood (Ember, Book 3) (by Jeanne DuPrau)

Nickie is sick of it all, so she gladly jumps at the opportunity to travel to Yonwood, North Carolina, with her aunt to ready their ancestral home for sale. Nickie, however, has other plans -- she hopes to convince her family to keep the home and move there, away from the city and the war.

But the war has come to Yonwood too, as an old woman has visions of destruction, and her friend, Mrs. Beeson, interprets these visions as commands from God to insulate the town with goodness. Nickie wants to change the world, and helping Mrs. Beeson root out wrongness in the town seems the way to do it.

Ignoring Ember, though, and taking the book on its own terms, this is a fascinating allegory with much to say to 21st-century children growing up in a world filled with terrorism and religious fanaticism. As in the previous book in this series, The People of Sparks, the ways in which fear can lead essentially well-meaning people down the road to totalitarianism, intolerance, and acquiescence to evil are made clear. Less believable are the events in the larger world, especially the mystifying hints around what causes the country to pull back from the brink.